An object of the invention is to provide a cleaning liquid for semiconductor substrates having undergone a chemical mechanical polishing process, the cleaning liquid being excellent in corrosion prevention properties and defect suppression performance with respect to a metal film. Another object of the invention is to provide a method of cleaning semiconductor substrates having undergone a chemical mechanical polishing process. A cleaning liquid of the invention is used for semiconductor substrates having undergone a chemical mechanical polishing process and includes: an amine oxide compound that is a compound having an amine oxide group, or its salt; and at least one hydroxylamine compound selected from the group consisting of a hydroxylamine, a hydroxylamine derivative, and their salts, and the amine oxide compound content is 0.00001 to 0.15 mass % based on the total mass of the cleaning liquid.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A cleaning liquid for semiconductor substrates having undergone a chemical mechanical polishing process, the cleaning liquid comprising: an amine oxide compound that is a compound represented by Formula (2), or its salt; and at least one hydroxylamine compound selected from the group consisting of a hydroxylamine, a hydroxylamine derivative, and their salts, wherein a content of the amine oxide compound is 0.00001 to 0.15 mass % based on a total mass of the cleaning liquid:, where R3, R4 and R5 each independently represent an alkyl group having 1 to 6 carbon atoms, and two of R3, R4 and R5 may be bonded together to form a five- or six-membered nitrogen-containing non-aromatic ring that may have an alkyl group having 1 to 4 carbon atoms.
2. The cleaning liquid according to claim 1, wherein a mass ratio of the content of the amine oxide compound to a content of the at least one hydroxylamine compound is not less than 0.001.
3. The cleaning liquid according to claim 1, wherein the amine oxide compound comprises trimethylamine-N-oxide.
4. The cleaning liquid according to claim 1, wherein the content of the amine oxide compound is 0.00001 to 0.05 mass % based on the total mass of the cleaning liquid.
5. The cleaning liquid according to claim 1, wherein the hydroxylamine compound is a compound represented by Formula (3) or its salt:, , where R6 and R7 each independently represent a hydrogen atom or an organic group, and R6 and R7 may be bonded together to form a non-aromatic ring that may have a substituent.
6. The cleaning liquid according to claim 1, wherein the hydroxylamine compound comprises diethylhydroxylamine.
7. The cleaning liquid according to claim 1, wherein the cleaning liquid further comprises a chelating agent.
8. The cleaning liquid according to claim 7, wherein the chelating agent comprises an aminopolycarboxylic acid-based chelating agent or a phosphonic acid-based chelating agent.
9. The cleaning liquid according to claim 1, wherein the cleaning liquid further comprises a reducing agent.
10. The cleaning liquid according to claim 1, wherein the cleaning liquid further comprises two or more reducing agents.
11. The cleaning liquid according to claim 1, wherein the cleaning liquid further comprises a surfactant.
12. The cleaning liquid according to claim 1, wherein the cleaning liquid further comprises two or more surfactants.
13. The cleaning liquid according to claim 1, wherein the cleaning liquid further comprises at least one amine compound selected from the group consisting of a primary amine having a primary amino group in a molecule, a secondary amine having a secondary amino group in a molecule, a tertiary amine having a tertiary amino group in a molecule, a quaternary ammonium compound having a quaternary ammonium cation, and their salts.
14. The cleaning liquid according to claim 1, wherein the cleaning liquid further comprises a quaternary ammonium compound having a quaternary ammonium cation, or its salt.
15. The cleaning liquid according to claim 14, wherein the quaternary ammonium compound has an asymmetric structure.
16. The cleaning liquid according to claim 1, wherein the cleaning liquid further comprises at least one selected from the group consisting of a primary amine having a primary amino group in a molecule, a secondary amine having a secondary amino group in a molecule, a tertiary amine having a tertiary amino group in a molecule, and their salts.
17. The cleaning liquid according to claim 1, wherein the cleaning liquid further comprises water, and a content of the water is not less than 99.6 mass % based on the total mass of the cleaning liquid.
18. The cleaning liquid according to claim 1, wherein the cleaning liquid has a pH of 8.0 to 12.0 at 25° C.
19. A method of cleaning semiconductor substrates, the method comprising a step of cleaning a semiconductor substrate having undergone a chemical mechanical polishing process by applying the cleaning liquid according to claim 1 to the semiconductor substrate.
20. The method according to claim 19, wherein the semiconductor substrate has a metal film containing at least one metal selected from the group consisting of copper, cobalt, and tungsten.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
May 19, 2022
March 11, 2025
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.